Cyber Resilience

CVE-2025-45663

Netsurf-Browser Netsurf 3.11

Public PoC
Published
03 November 2025
Modified
05 November 2025
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS Score 0.0034 27th percentile
Risk Priority 50 floored blend · peak EPSS

Summary

CVE-2025-45663 is a medium-severity Heap Inspection (CWE-244) vulnerability in Netsurf-Browser Netsurf. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-4 (Information in Shared System Resources) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

An issue in NetSurf v3.11 causes the application to read uninitialized heap memory when creating a dom_event structure.

CWE(s)
CWE-244

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
attack.mitre.org →
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-29699Same product: Netsurf-Browser Netsurf
CVE-2024-51317Same product: Netsurf-Browser Netsurf
CVE-2025-1721Shared CWE-244
CVE-2026-20039Shared CWE-244
CVE-2025-26304Shared CWE-244
CVE-2025-36083Shared CWE-244
CVE-2025-1719Shared CWE-244
CVE-2025-1722Shared CWE-244
CVE-2023-20070Shared CWE-244
CVE-2023-20031Shared CWE-244

Affected Assets

netsurf-browser
netsurf
3.11

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SC-4 Information in Shared System Resources good match

SC-4 requires mechanisms that stop unintended transfer of sensitive data through shared resources such as heap memory reused after realloc.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-10 mostly match
prevents

Explicit example of removing confidential data from process memory directly prevents heap inspection exposure.

PR.PS-06 partial match
prevents

Secure SDLC practices encompass proper sensitive-memory handling but fixing this single CWE does not achieve the control.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.10 Information deletion partial match
prevents

Explicitly requires secure deletion of sensitive data, directly addressing improper heap clearing.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC processes can incorporate memory-safety requirements but do not specifically mandate heap clearing.

A.8.28 Secure coding partial match
prevents

Mandates secure coding practices that include proper memory sanitization before release.

A.8.27 Secure system architecture and engineering principles none match
none

Secure architecture principles may reduce exposure but do not prescribe explicit heap-clearing techniques.

References